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Primordial black holes, formed from rare peaks in the primordial fluctuations $\zeta$, are non-rotating at zeroth order in $\zeta_rms$. We show that the spin also vanishes at first order in $\zeta_rms$, suggesting the dimensionless spin parameter $a_rms \sim \zeta_rms^2$. We identify one quadratic contribution to the spin by calculating (and extrapolating to the formation time) the torque on a black hole due to ambient acoustic waves. For a reasonable density of primordial black holes this implies a percent level spin parameter.
